1. Field of Invention
In-vehicle operation of a radio (wireless) telephone handset, and in particular enhancing the operation of a cellular telephone handset by using an in-vehicle data terminal that is associated with a motor vehicle fleet management system.
2. Related Art
In-vehicle fleet management systems that communicate the vehicle's location, for example as determined by using Global Positioning System (GPS) information, to a central location are known. Such systems (e.g., the FLEETASAP™ motor vehicle fleet management system produced by At Road, Inc., Fremont, Calif.) typically include a location manager that determines the vehicle position and a data terminal electrically coupled to the location manager. A wireless modem in the location manager typically facilitates communication between the location manager and a central computer platform configured to act as a server (provider of specific facilities to client devices) via, for example, a cellular telephone system. Thus both the vehicle position and the data input on the data terminal are communicated to the central server. In addition, the server communicates data (e.g., messages) to the location manager for output on the data terminal. Fleet management systems also typically offer two-way message capability between the fleet operator and individual fleet vehicle drivers.
Also known are wireless (radio) handsets (e.g., cellular telephone handsets, personal digital assistants) that can receive and output text messages. For example, the 1.8 GHz Personal Communications System (PCS) includes the dedicated use, low bandwidth, bitstream Short Message Service (SMS; defined in TIA/EIA/IS-707). Using the SMS, messages originating from a server, or in the form of electronic mail (email) from a personal computer, are routed to the PCS handset for output on the handset display.
Wireless handsets have become increasingly smaller. This small size often makes handset operation difficult, especially in a motor vehicle. For example, handset dial pad buttons are small. In addition, handset visual displays (e.g., liquid crystal display) are small, and text messages that are output on the displays are difficult to read due to small character size and the limited amount of characters that are displayed. In-vehicle handset operation and message display is further limited during poor lighting conditions such as sunlight glare or during nighttime. Furthermore, handsets are often mounted in holders attached to the vehicle dashboard so that the handset is difficult to access and view from the driver's position. Therefore, it is desirable to provide enhanced in-vehicle wireless telephone handset operation. It is also desirable that such enhanced operation include enhanced text message output. Since a device external to the handset is used to provide such operating enhancements, it is desirable to warn the vehicle operator when the handset is not connected to the enhancing device.